Battery modules obtained by connecting a plurality of electric cells side by side are used as power source apparatuses of electric automobiles and hybrid cars. In such battery modules, if the temperature of electric cells rises to a high temperature, the lifetime and the like of the electric cells are adversely affected, and thus a means has been devised in which the temperatures of the electric cells are monitored using a temperature detection module equipped with a thermistor, and a means disclosed in Patent Document 1 (JP2013-157123A) below is known, for example.
The temperature detection module includes a thermistor mounting member that is made of a synthetic resin and is provided with a plurality of thermistor holding portions and an electrical wire routing path, and has a structure in which a thermistor is accommodated in each of the thermistor holding portions in a form in which the thermistors are biased in a manner of elastic movement toward the electric cells, and thermistor electrical wires (lead wires) drawn from the thermistors are routed along the electrical wire routing path in one direction. When this temperature detection module is mounted on an upper surface of the battery module, the thermistors are elastically pressed against the corresponding electric cells, and the temperatures of the electric cells are individually detected as appropriate. Herein, drawing ends of the thermistor electrical wires that are drawn from the thermistors are provided with excess length portions so as to allow the movement of the thermistors.